Method and apparatus for distributed data archiving

ABSTRACT

An archive system is provided for long term storage of large amounts of data that is particularly suited for multi-year storage of medical data such as cardiac images, patient demographics and reports. One or more digital versatile disks (DVDs) may be employed as the storage media. In the archival process, all of the data for a particular patient, procedure or study is stored and uniquely identified within one DVD. Each DVD may have an executable program stored thereon for independently accessing the archived data from the selected DVD. Before the DVD is recorded, the data to be archived is segmented into a plurality of information groups where each group is based on data for the particular patient, procedure or study. Then, the DVD is reviewed to determine whether a sufficient amount of storage space is present to ensure that the information group will be entirely stored within one DVD.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims priority under 35 U.S.C. §119(e) to provisionalpatent application Ser. No. 60/228,631 filed Aug. 29, 2000, thedisclosure of which is hereby incorporated by reference.

BACKGROUND OF THE INVENTION

The diagnosis and treatment of cardiac disease requires the acquisitionof large amounts of data about the patient's medical condition. Thisdata typically consists of medical images, patient information andclinical reports. The treatments of a single patient's disease cangenerate 1,000,000,000 bytes (1 Gbyte) or more of digital information.Millions of patients are treated worldwide each year for cardiacdisease. Many other medical conditions exist for which similarquantities of data are maintained. The storage and management of suchpatient data requires more capacity than can be cost effectivelydeployed using standard magnetic disk technology.

The standard industry solution to this problem has been to combine smallamounts of hard disk storage with large amounts of low cost magnetictape storage. This combination of storage technology is implemented as astorage hierarchy. The premise of such a system is that newer data isaccessed more frequently than old data. The typical Hierarchical StorageManagement (HSM) system software used to manage a storage hierarchymoves data from the more costly hard disk storage to tape storage basedon heuristics such as age of the data or last access time. HSM supportsthis type of data flow transparently to the software application thatgenerates the data. In other words, if the data were a word processeddocument called mydoc.doc, access to a document is achieved by openingthe file mydoc.doc. The HSM system provides access to data by restoringthe data from tape to disk automatically. This transparency is createdby a virtual file system (VFS). The VFS concatenates all of the storagein the hierarchy into one logical disk drive. The only apparentdifference to the user is speed of access; files on the hard disk areaccessed very quickly while files on the tape library are accessed withlengthy delays.

The transparency created by HSM creates problems due to monolithicaccess, proprietary formats, replication difficulties, and poorperformance which make HSM poorly suited to mission critical medicalimage storage environments. Specifically, the primary design principleof HSM is to create transparency so that existing software does not needto be rewritten to take advantage of the large storage system. Thetransparency is achieved by aggregating all individual storage units(single tapes in a robotic library system plus hard disk(s)) into asingle file system. As a result, files will be spread across all of thestorage units in the hierarchy.

This design creates a situation where an individual storage unit is onlymeaningful in the context of the HSM system, which created it.Therefore, if a tape is removed from an HSM managed library, the tapewill have no meaning outside of this HSM managed library and the tapemust be restored to the HSM system to be accessed. HSM manufacturersoften use proprietary or limited logical formats on each storage unit sothat tapes cannot be read without the HSM software.

Although HSM often has a system for routine backup, HSM is viewed as aseparate function from the backup and recovery management needed in theevent of a catastrophe. As a result, HSM systems fail to provide for thecreation of offsite copies of tapes for efficiently recreating the HSMin the event of a disaster. The complex data flow in HSM that movesfiles back and forth between levels in the hierarchy results in poorperformance. An application must wait for a file to be fully restoredfrom tape to disk before accessing the first byte of information.

BRIEF SUMMARY OF THE INVENTION

The archive system according to the present invention provides long termstorage for large amounts of data. This system is particularly suitedfor multi-year storage of medical data such as cardiac images, patientdemographics and reports. In a preferred embodiment, the archive systemof the present disclosure employs one or more digital versatile disks(DVDs) as the storage media. In the archival process, all of the datafor a particular patient, procedure or study is stored within one DVDand each DVD is uniquely identified. Also, each DVD may have anexecutable program stored thereon for independently accessing thearchived data from the selected DVD.

Before all of the data is archived, the present archive system segmentsthe data into a plurality of information groups where each group isbased on data for the particular patient, procedure or study. Once theinformation groups are formed, each group is stored on a storage medium(DVD). Before recording an information group on a DVD, the DVD isreviewed to determine whether a sufficient amount of storage space ispresent to ensure that the information group will be entirely storedwithin one DVD. Once a DVD is found with enough storage capacity, theinformation group is stored thereon. This process is repeated for eachinformation group. Although other storage media may be used, DVDs arepreferable because their storage capacity is sufficient to store atleast one typical information group.

In addition to the one or more information groups stored on each DVD,the unique identification and executable programs stored thereon alloweach DVD or subsets of DVDs to be accessed independent from the otherDVDs for viewing and printing the data on other processors or workstations. Also, the data from DVDs or DVD subsets created by differentprocessors may be merged and modified to create new information groups.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

The invention will be more fully understood by reference to thefollowing detailed description of the invention in conjunction with thedrawings, of which:

FIGS. 1( a)-1(d) illustrate configurations for the archival storagemedia according to embodiments of the present invention;

FIG. 2 illustrates an archival system according to an embodiment of thepresent invention;

FIG. 3 is a flow chart of an archive session according to an embodimentof the present invention; and

FIG. 4 is a flow chart of an archive selection according to anembodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

To provide the storage of large amounts of data in the archive systemaccording to the embodiments of the present invention, the data issegmented into information groups and stored onto archival storagemedia. For instance, data may be accessed from one or more externalsource(s) and segmented into information groups based on a desiredprocedure, study or patient.

FIGS. 1( a)-1(b) illustrate configurations for storing such informationgroups in archival storage media by the present archive system. In FIG.1( a), retrieved data segmented into information groups 20A, 20B, 20C,20D, and 20E are recorded onto archival storage media 10 and 12. Four ofthe information groups 20A, 20B, 20C, and 20D and an index file 14including an identifier, a database file, a data program, an imageplayer, and/or other programs files are recorded on the archival storagemedium 10 before a predetermined storage capacity is reached on themedium 10. The index file 14 allows the information groups 20A, 20B,20C, and 20D stored on the archival storage medium 10 to be accessed,processed and viewed on a wide range of personal computers and operatingsystems.

The archival storage medium 10 is preferably a DVD, which is capable ofstoring one or more information groups. However, other archival storagemedia may be used as long as sufficient capacity is provided for storingat least one information group.

Before recording an information group, the recording processordetermines whether the entire information group is able to be stored onthe medium without exceeding its storage capacity. In the presentillustrative example of FIG. 1( a), the four information groups 20A,20B, 20C, and 20D are recorded onto the archival storage medium 10without exceeding its storage capacity. In this example, the informationgroup 20E cannot be recorded on the archival storage medium 10 withoutexceeding its storage capacity. Therefore, the information group 20E andan index file 16 including an identifier, a database file, a dataprogram, an image player, and/or other programs files are recorded onthe archival storage medium 12 as long as its storage capacity is notexceeded. The index file 16 allows the information group 20E to beaccessed, processed, and viewed independently. This system and storageconfiguration ensures that each information group and the necessaryprograms and files to retrieve and view the respective information areentirely stored within one archival storage medium. As a result, eacharchival storage medium stands alone and is capable of being utilizedindependent from the other archival storage media so that itsinformation can be accessed, viewed and processed.

The present archive system also allows for information and subsets ofinformation stored on one or more disks to be accessed and merged toform new information groups. For instance, the information group 20Cfrom the archival storage medium 10 can be accessed and recorded ontoanother archival storage medium 30 as illustrated in FIG. 1( b). Similarto the above described archival storage media, an index file 32 isrecorded on the archival storage medium 30 to include an identifier, adatabase file, a data program, an image player, and/or other programsfiles for accessing, processing and viewing the information group 20C.

FIG. 2 illustrates an archive system according to one embodiment of thepresent invention. A user interface (UI) 200 controls the present systemfor retrieving or receiving information from one or more source(s) 270.The UI 200 may be a conventional personal computer and the informationsource(s) 270 may be any type of device or component that supplies thedesired data or information in a readable form to the UI 200. Thearchive system may be connected with network components 280, such asworkstations, UIs, information sources and other network compatibledevices. For example, when the desired data is in the medicalenvironment, the information source(s) 270 may be a readable compactdisk (CD) of patient reports or image data (such as CT, MR, CR, X-RayAngiography and rf, PET, NM, US for example) images from scanners, X-Raymachines and the like.

The UI 200 communicates with a memory system 210 and a media recorder260 for storing and recording the information from the informationsource(s) 270. The memory system 210 may be a hard disk, redundant arrayof independent disks (RAID), or external memory devices that aresupported by the UI 200. The memory system 210 provides on-line storagefor the initial creation of information file based on the data transferfrom the information source(s) 270. The on-line information stored inthe memory system 210 may be later accessed by the UI 200 based onuniversal naming convention (UNC) path of the memory system 210. Themedia recorder 260 is dependent upon the type of archival storage mediathat is used. When DVDs are used as the archival storage media, themedia recorder 260 is a DVD recorder that is supported by the UI 200.After the DVDs are recorded, they may be physically placed in jukeboxstorage 220 as represented by the dashed line.

Due to the storage limitations of the memory system 210, a jukeboxstorage 220 is provided for retaining selected ones of the archivalstorage media. The UI 200 supports and communicates with the jukeboxstorage. Before the memory system 210 reaches its storage capacity, themedia recorder 260 records one or more information groups onto at leastone archival storage medium, such as a DVD. After the DVDs are recorded,they are mounted in the jukebox storage 220 such that the information onthe DVDs are in “near-line” storage. Thereafter, the information on aDVD mounted in the jukebox storage 220 can be accessed by the UI 200based on the UNC path of the DVD within the jukebox storage 220. One ormore jukebox storage units may be incorporated into a single archivesystem.

Information may be present in the on-line and near-line state at thesame time. When near-line information is deleted, the near-line stateends for that particular information. However, such near-lineinformation will not be deleted but will receive an “end” date when theinformation is no longer valid.

Archive storage 230 is provided for off-line storage of the DVDs. Thearchive storage 230 may be shelf-type storage remote from the rest ofthe system. The archive storage 230 may include either duplicate copiesof DVDs mounted in the jukebox storage 220 so that the informationappears in both near-line and off-line states or DVDs that are removedfrom the jukebox storage 220 and are present only in the archive storage230. The DVDs are physically placed in the archive storage from eitherthe jukebox storage 220 or the media recorder 260 as represented by thedashed lines. Alternatively, some form of robotic manipulator may beemployed to exchange archival storage media between “near-line” and“off-line” status. When the information contained on an off-line DVD isattempted to be accessed by the UI 200, a volume label of the DVD thatwas removed or copied from the jukebox storage 220 will result,indicating its “off-line” status.

The present archive system allows for a virtual archive 100 to beprovided as illustrated in FIG. 1( c). The virtual archive 100 mayinclude a set 110 of information groups 110A, 110B, and 110C that are incombinations of on-line, near-line, and off-line states. In one example,information group 110A is stored on-line and information groups 110B and110C are stored near-line. In this case, a primary database 120 isstored in a separate medium from the other information groups 110A,110B, and 110C of the virtual archive 100. Within each of theinformation groups 110A, 110B, and 110C, local databases 112A, 112B, and112C are respectively stored. The primary database 120 has a databasefile for the constituent information groups of the virtual archive 100to all of the local databases 112A, 112B, and 112C, the status of thestorage media, the recorded time of the storage media, the type of datain the storage media, and other descriptive references relating to thisvirtual archive 100. Thereby, all of the related information groups110A, 110B, and 110C can be readily accessed and retrieved despite beingretained in different storage states.

The virtual archive 100 may be merged and modified as illustrated inFIG. 1( d). In this example, two information groups 110A and 110B may beretrieved from the virtual archive 100 to create another virtual archive150. A set 160 of information groups 160A and 160B is created asduplicates or subsets from the information groups 110A and 110B. Asabove, the virtual archive 150 includes a primary database 170 forrelating local databases 162A and 162B contained within the informationgroups 160A and 160B and retained in different storage states.Accordingly, the virtual archive 150 includes the information groups160A and 160B while the information groups 110A, 110B, and 110C in thevirtual archive 100 remain intact.

When the media recorder 260 records a DVD, a unique identifier isencoded thereon. This identifier uniquely identifies each DVD so that aDVD can be tracked, managed, and interchanged at different locations.Thereby, DVDs from one archive system can be transparently accessedand/or merged with DVDs from another archive system. In one embodiment,the unique identifier is a concatenation of a distinctly assigned volumelabel followed by values representing the recorded year, day within theyear, hour, minute within the hour, seconds, and milliseconds. Forexample, a DVD assigned a volume label of 1.2.840.113815 on Sep. 22,1999 at 9:12:46.157 AM would have the following identifier:

-   -   1.2.840.113815.1999265091246157.        In this example, no two primary DVD copies will have the same        identifier. The identifier is machine-readable and conforms to        the universal disk format (UDF) standard volume label format for        removable media.

Each DVD also includes a self-contained database file for holding all ofthe meta-data required to completely describe a procedure or studystored on that DVD. For instance, in the medical environment, theself-contained database may include all of the demographics for apatient required to adequately review the clinical procedures, stored onthat medium. Digital Image Communications for Medicine (DICOM-3) ispreferably used to implement this database file. DICOM-3 is a knownstandard for enhancing the ability of medical imaging devices andequipment to transfer medical images and information between systems,such as between a computer tomography (CT) scanner, a workstation, and aprinter.

By requiring each information group or the information for each patientto be entirely contained on one storage medium or DVD, it is possible toutilize the self-contained database file for independently accessing,viewing, and processing each DVD. This addresses a deficiency associatedwith conventional HSM based systems using DICOM-3, with which patientdata often spans two media, such as two magnetic tape units. Each DVDmay be exchanged between archive systems without secondary databasetransactions to fully describe a procedure or study. Also, standardclinical imaging stations may directly read the DVDs, allowing review ofarchived images outside of the archive system in which it was originallycreated. This is in contrast to prior art systems in which the contentsof one storage mechanism such as a magnetic tape are meaningless outsidethe context of the archive in which it was created. In the event offailure of the primary archive system according to the presentinvention, information from the DVD may be retrieved on a differentarchive system, computer, or imaging station.

System auditor data is also recorded on the DVDs for allowinginformation to be mounted in or removed from an archive system.Information from the DVD's comprising the archive is automaticallysynchronized to the primary information database whenever information isadded to or read from a DVD. The system auditor allows DVDs fromdifferent archives to be combined to create a new archive with a singlecoherent primary database. When a DVD is removed from the system, thesystem auditor changes the location and status information for that DVDin the primary database to the off-line.

The archive system may also include software for automated network-basedmedia duplication. This duplication software allows for the creation ofexact duplicates of the DVDs stored in the archive system on a networkattached thereto. Thereby, exact copies of primary archival storagemedia may be created and stored at different physical locations so thata complete restoration of the archived information may be performed inthe event of a disaster. When using the duplication software incombination with the system auditor, an empty primary database may becompletely rebuilt from information stored on archived storage media. Ifan archive system is completely destroyed, duplicate off-line media canbe used to completely reproduce the original information system on a newarchive system.

An embedded image player is also recorded on the DVDs in this example.The embedded image player includes a computer program for initiating thedisplay of the meta-data, image data, and associated test resultscontained on the DVD. Thus, the patient data contained on the DVDs maybe accessed and reviewed at any later time without specialized equipmentor software.

The archive system selects information to be archived based onpredefined system settings. These settings may include: archive oldestor newest first; the number of archival storage media to be written;media storage capacity; run time; media information staging directory;whether to write to the media or location to move files; and UNC pathfor study to identifier text file for tracking the media.

In one embodiment of the present archive system, the archiving processruns as a Windows NT service from the UI 200. The archiving process isconfigured to run without user interaction with provisions for manuallystarting, stopping, pausing, and continuing through the UI 200. Anapplication may be provided to update the status of the archivingprocess. FIG. 3 is a flow chart illustrating an example of an archivesession according to an embodiment of the present invention. The archivesession is initiated at step 300. A search and compilation of studies orprocedures are conducted at step 310. After the studies or proceduresare obtained, the number of archival storage media or DVDs needed forthese studies or procedures is established at step 320. The studiesand/or procedures are staged and segmented into information groups atstep 330 and any images are created at step 340. At step 350, theinformation groups are written on each DVD.

After writing one or more information groups on a DVD, that DVD isverified at step 360 as to whether the writing has been successfullycompleted. For example, verification determines whether each intendedinformation group is contained within the DVD. If the DVD is notverified, it is determined whether writing to the DVD is to be retriedat step 364. If a retry is desired or appropriate, writing to the DVD isrepeated at step 350. If the DVD is verified or if a retry is notdesired, the information group locations are updated at step 370. Nextat step 380, the identifier and index files are recorded before thearchive session ends at step 390.

The archive session may be configured to start archiving at a specifiedtime each day. When the archiving process starts, a number of specifiedDVDs are written as long as information is available based on aselection process in one embodiment of the present invention. Asillustrated in FIG. 4, the present archive selection is initiated atstep 400. At step 410, it is determined whether any information groupsare available. One information group is selected at step 420 when it isdetermined to be available. At step 430, it is determined whether theselected information group has already been archived. If the selectedinformation group has not been archived, it is determined whether thisinformation group was created after an archive time setting has expired.This archive time setting is a predefined value corresponding to adesired minimum time to age before archiving is performed.

If the selected information group was created before the archive timesetting expired or was previously archived, the process increments tothe next information group, if available, at step 425 without storingthe information group for further processing. If the selectedinformation group was created after the archive time setting expired andwas not previously archived, this information group is retained forfurther processing at step 445.

When no further information groups are determined to be available atstep 410, the archiving order is determined at step 450. If thearchiving process is configured to archive the oldest information groupsfirst, the information groups are sorted in ascending order by date andtime at step 453. Otherwise, the archiving process is configured toarchive the oldest information groups last and the information groupsare sorted in descending order by date and time at step 456. Othermetrics may be used to define the archive order.

The first of the sorted information group is selected at step 458 andthe amount of available storage capacity for a selected DVD is comparedto the selected information group. The available storage capacity isdetermined by using a predefined percentage full value for the DVD. Theamount of storage capacity remaining if the information group were to berecorded onto the DVD is compared to the percentage full value. Theinformation group is recorded onto the DVD at step 470 if the percentagefull value of the DVD will not be exceeded. However, if recording theinformation group onto the selected DVD would exceed the percentage fullvalue, another DVD is selected at step 464 and then the availablestorage capacity of the new DVD is determined. Accordingly, theinformation group will not span across two or more DVDs and eachinformation group will be entirely contained within one DVD.

Verification of writing to the DVD is performed at step 480. If writingof the information group is not verified, it is determined whether aretry of writing the information group is desired at step 482. If theinformation group recorded onto the DVD is verified at step 480, theprocess attempts to increment to the next information group at step 484and determines whether another information group is available at step490. If another information group is available, the next informationgroup is selected at step 458. However, if no more information groupsare determined to be available at step 490, the archive selection endsat step 499.

It will be apparent to those skilled in the art that other modificationsto and variations of the above-described techniques are possible withoutdeparting from the inventive concepts disclosed herein. Accordingly, theinvention should be viewed as limited solely by the scope and spirit ofthe appended claims.

1. A method for distributed data archiving, comprising the steps of:accessing patient medical data from at least one external source;segmenting the patient medical data into a plurality of informationgroups with each information group corresponding to information about aparticular patient; providing a data archiving system comprised of aplurality of archival storage media; storing each information group ontoan archival storage media, said information groups being stored on saidarchival storage media with each information group having anidentification, the identification being unique from all otherinformation groups stored within said archival storage media and allother archival storage media, enabling said information groups to beindependently accessed, within or without the data archiving system inwhich the information groups were created, and each information groupbeing stored entirely only on one of said plurality of archival storagemedia by the following steps: determining an available storage capacityof the storage medium, comparing the available storage capacity of thestorage medium to the information group that is to be stored, recordingthe information group on the selected storage medium only if a size ofthe information group is smaller than the available storage capacity ofthe storage medium, and selecting another storage medium if the size ofthe information group is larger than the available storage capacity ofthe storage medium; encoding a unique identifier on said one of saidplurality of archival storage media to uniquely identify the storagemedium from all other storage media, said encoding step includingrecording an index file having at least an identifier, a data program,and a self-contained database file for each of said information groupson said one of said plurality of archival storage media, wherein thedatabase file recorded on the archival storage media containsinformation describing clinical procedures of the patient medical datastored on the archival storage media, and wherein the database file isimplemented by Digital Image Communications for Medicine; andindependently accessing said one of said plurality of archival storagemedia at a site other than said data archiving system by reading saidindex file.
 2. A method according to claim 1, wherein said archivalstorage media comprise digital versatile disks (DVDs).
 3. A methodaccording to claim 1, wherein said information groups comprise meta-dataand image data.
 4. A method according to claim 3, wherein each of saidarchival storage media comprises an embedded image player for viewingthe images.
 5. A method according to claim 3, wherein each of saidarchival storage media comprises an application for interpreting themeta-data.
 6. A method according to claim 1, further comprising the stepof creating an executable program on each of said archival storage mediafor retrieving said information groups stored thereon.
 7. A methodaccording to claim 1, further comprising the step of recording saidinformation groups on said archival storage media as near-line andoff-line storage.
 8. A method according to claim 1, wherein a firstsubset of said archival storage media is provided as on-line storage. 9.A method according to claim 8, wherein said on-line storage comprises ahard disk.
 10. A method according to claim 1, wherein a second subset ofsaid archival storage media is provided as near-line storage.
 11. Amethod according to claim 10, wherein said near-line storage comprises ajukebox storage for providing sequentially selectable access to at leastone archival storage media.
 12. A method according to claim 1, wherein athird subset of said archival storage media is provided as off-linestorage.
 13. A method according to claim 12, wherein said off-linestorage comprises shelf storage for said archival storage media.
 14. Amethod according to claim 1 including independently accessing said oneof said plurality of archival storage media by accessing the archivalstorage media at a clinical imaging station allowing a review ofarchived images outside of the data archiving system in which thearchival storage media was originally created.
 15. A method according toclaim 1 including encoding an index file that also has an image player.16. A method according to claim 15 wherein the database file holds allof meta-data required to completely describe a procedure or study storedon the archival storage media.
 17. A method according to claim 1 whereinthe identifier comprises a volume label.
 18. A method according to claim1, wherein the database file further contains patient demographicinformation relevant to the clinical procedures recorded on the archivalstorage media.
 19. A distributed data archiving system, comprising: auser interface for controlling the system, said user interface includinga processor for receiving patient medical data from a plurality ofexternal sources and segmenting the patient medical data into aplurality of information groups; and a memory storage comprised of aplurality of separate archival storage media for storing informationgroups with each information group corresponding to information about aparticular patient, each information group being stored entirely only onone of said plurality of archival storage media by determining anavailable storage capacity of the storage medium, comparing theavailable storage capacity of the storage medium to the informationgroup that is to be stored, recording the information group on theselected storage medium only if a size of the information group issmaller than the available storage capacity of the storage medium, andselecting another storage medium if the size of the information group islarger than the available storage capacity of the storage medium, eacharchival storage media comprising: 1) a group informationidentification, the group information identification being unique fromall other information groups stored within said archival storage mediaand all other archival storage media; 2) a unique identifier to uniquelyidentify the archival storage media from all other archival storagemedia; and 3) an index file having a data program and a self-containeddatabase file, for each of said information groups, containinginformation describing clinical procedures of the information groupsstored on the archival storage media, said information groups areindependently accessed, within or without the data archiving system inwhich the information groups were created, wherein the database file isimplemented by Digital Image Communications for Medicine, and whereinthe archival storage media is independently accessed at a site otherthan said data archiving system by reading said index file.
 20. Adistributed data archiving system according to claim 19, wherein saiduser interface comprises a personal computer.
 21. A distributed dataarchiving system according to claim 19, wherein said external sourcescomprises a workstation.
 22. A distributed data archiving systemaccording to claim 19, wherein said external sources comprises a networkcompatible device.
 23. A distributed data archiving system according toclaim 19, wherein said memory storage comprises on-line, near-line, andoff-line storage media.
 24. A distributed data archiving systemaccording to claim 23, wherein said on-line storage media comprises ahard disk.
 25. A distributed data archiving system according to claim23, wherein said on-line storage media comprises a redundant array ofindependent disks.
 26. A distributed data archiving system according toclaim 23, wherein said near line storage media comprises a jukeboxstorage for providing sequentially selectable access to said archivalstorage media.
 27. A distributed data archiving system according toclaim 23, wherein said off-line storage media comprises shelf storagefor said archival storage media.
 28. A distributed data archiving systemaccording to claim 23, further comprising a media recorder for recordingsaid information groups on said archival storage media as near-line andoff-line archival storage media.
 29. A distributed data archiving systemaccording to claim 19, wherein said user interface creates an executableprogram for retrieving said information groups stored on said archivalstorage media and stores said executable program on said archivalstorage media.
 30. A distributed data archiving system according toclaim 19, wherein said archival storage media comprise digital versatiledisks (DVDs).
 31. A distributed data archiving system according to claim19 wherein the same information group is stored on more than one storagemedium having a different unique identifier associated with each.
 32. Adistributed data archiving system according to claim 19, wherein thedatabase file further contains patient demographic information relevantto the clinical procedures recorded on the archival storage media.